SPWG SHORT CIRCUIT CASE BUILDING AND DEVELOPMENT - 2014

1. SPWG SHORT CIRCUIT CASE BUILDINGAND DEVELOPMENT - 2014 Qiuli Yu and Jay Teixeira ERCOT

2. Topics • Case Building Process for Current Year and Future Year Cases • Current Year Case Process • Future Year Case Process • Software Requirement/Update • Case Development and Achievement in 2014 • Generator Synchronization with SSWG • Sequence Impedance • Grounding Impedance • Voltage Profile • Current Limit • Wind Farm Modeling—WTG Equivalent Circuit

3. Case Building Process – Current Year • Time Span • From Mid-December (Previous Year) to Mid-April (Current Year) • Total 6 Passes – Pass 0, 1-4, and Final Pass • Two Weeks for TSP to Submit Change Files • One Week for ERCOT to Develop Short Circuit Model • Base Case • Future Year Final Pass created last year • Example: 2015 CY base case = SPWG_2015_FY_UPDATED_07032014_FINAL

4. Case Building Process – Future Year • Time Span • From Mid-April (Current Year) to Mid-July (Current Year) • Total 6 Passes – Pass 0,1-4, and Final Pass • One Week for TSP to Submit Change Files • One Week for ERCOT to Develop Short Circuit Model • Base Case • Current Year Final Pass created in current year • Example: 2016 FY base case = SPWG_2015_CY_UPDATED_04xx2015_FINAL

5. Summary – Base Cases for CY and FY

6. Summary – Change Files for 2016-2020 FY Cases Cases Built Last Year 2015 FY 2015 FY 2015 FY 2015 FY 2019 FY 2018 FY 2016 FY 2017 FY 2018 CHF 2016 CHF 2019 CHF 2017 CHF 2015 CY 2015 CY 2017 FY 2016 FY 2016 CHF 2017 CHF

7. Software Requirement and update • ERCOT and TSPs: • PSSE v33 • ASPEN OneLiner V12.4 • ERCOT: • RARF Database • MODFileBuilder v33

8. Case Development and Achievement in 2014 • Add generators to synchronize with SSWG cases • Grandview, PH1, PH2, WindThorst, Stephens Ranch, Spinning Spur Wind 3, Long Horn, RenTech Project, Hereford,…… • Most new gens are wind farms • Some gens with incomplete RARF data have not been modeled • Sequence Impedance Data (P.U.) • Come from RARF submitted by REs • Some verification rules: • X”<X’<X • R0 &X0 may be 99999 for WTG • Process: • Query out from RARF database and manually copy/paste to PSSE file

9. Case Development and Achievement in 2014 (continue…)

10. Case Development and Achievement in 2014 (continue…) • Voltage Profile • Voltage profile is the Vsched (pu) in the Machine Tab in PSSE • Come from SSWG base case (PSSE raw file) • Process: Manually copy from SSWG base case and paste into SPWG PSSE file

11. Case Development and Achievement in 2014 (continue…)

12. Wind Farm Modeling—WTG at Different kV • Currently WTG are modeled at different kV levels in SPWG: • 0.575 kV • 0.690 kV • 34.5 kV

13. Wind Farm Modeling—WTG Equivalent Circuit (Future Work) • Equivalent Circuit and Parameters (One Feeder): • Individual WTG will be aggregated per feeders • Topology and Parameters – RARF • Hope to complete December of 2014, depending on RARF data submission

14. Possible Methods for WTG Equivalent Circuit Development • Method 1 – Fault Current Simulation Using PowerWorld

15. Possible Methods for WTG Equivalent Circuit Development • Method 2 – Equivalent impedance calculation based on Wind Farm topology and collector system parameters

16. Possible Methods for WTG Equivalent Circuit Development • Method 3 – Use equivalent network function in PSSE/PowerWorld? • Any Comments?

17. Questions QUESTIONS?